There may or may not be a specialist regulator: one option is to extend the OFT's remit.Effective action will depend partly on these triggers - how to define them specifically, and who they will catch - and partly on what happens to the "assessment" when made. On the key issue of how to measure media markets, the White Paper failed to back a particular yardstick. The triggers for the media sector as a whole (embracing all three) are determined as 10 per cent of the UK market, or 20 per cent of a geographical market embracing all three; 20 per cent of an individual sector - meaning it seems the UK as a whole - is also a trigger.Thus the argument is that, in the long term, the media will be incorporated into the body of UK competition law as it affects monopoly and merger. The market shares for triggering intervention are defined by a mixture of shares in media as a whole (defined as television, press and radio) and shares of these sectors individually. A separate quango might be established alongside the other UK authorities, or incorporated in them.Contributors to an Institute of Enconomic Affairs book on media concentration argue strongly against any further extension of regulation But accepting the premise that new rules to trigger regulatory action are needed to safeguard diversity in the media, do the proposals promise effective action?The White Paper focuses on market shares above which a regulator must assess the public interest, whether the level is reached already or through merger or acquisition.

At the same time, some liberalisation of existing ownership rules was proposed. The Broadcasting Bill, now going through Parliament, contemplates abolishing "the existing structure of detailed rules", substituting a set of "triggers on ownership levels in the media market as a whole, and sector triggers, which when actually or prospectively exceeded would mean any media merger would be `subject to approval by an independent media regulator' to determine the public interest". Thus, the special treatment of newspaper mergers in UK law would be extended, in modified form, to other media. In May 1995 the Government's White Paper on Media Ownership concluded that "to preserve the diversity of the broadcast and press media in the UK", there was a "continuing case for specific regulations governing media ownership beyond those which are applied by the general competition law". Figures, due next week, are expected to be disappointing and could prompt 14 per cent shareholder SHV, a Dutch investment group, to move for control. Last year SHV, which has 60 per cent of the Makro cash and carry business, attempted to gain control by pumping warehouses into N&P in exchange for shares.Avocet Mining, with interests in gold and tungsten mines, made a quiet debut, closing at 3p above its 240p placing price.. Clubhaus, the golf group, was the most heavily traded share; there was talk of an institution buying shares at 6.5p.

The firm, split from the Ex-Lands property group, has taken a five-year lease to manage Nizels Golf Club near Tonbridge, Kent.Nurdin & Peacock, the cash and carry group, edged 2p higher to 178p. Firth, the steel business, was also unchanged at 47p as Malaysian investment fund, Sri Inderajaya, nudged its stake to 14.13 per cent.Ideal Hardware improved 33p to 545p after an agency cross at 530p. Sage, as NatWest Securities said buy, improved a further 9p to 404p.Pizza Express jumped 19p to 344p on suggestions Janus Capital, the US fund which has built an 18.57 per cent stake in the JD Wetherspoon pubs group, had acquired a taste for the pizza chain.Mid-States, running a car parts operation in the US, held at 39p as Botton International Investments, the vehicle of Irish entrepreneur Dermot Desmond, lifted its interest to 16.06 per cent. Firecrest, an Internet group, fell 7p to 78p, reflecting the Stock Exchange censure of chief executive, Roy Capper. BSkyB jumped 11p to 447p, helped by the Liverpool/Newcastle Utd televised clash which lifted Manchester Utd 6p to 293p. Carlton Communications rose 16p to 480p.Eurotunnel ignored its debt mountain, gaining 3p to 66p on its record trading last month.Continuing talk of disposals lifted WH Smith 12p to 464p and Great Universal Stores, up 17p to 684p, was thought to be helped by positive comments from Barclays de Zoete Wedd and Cazenove.Superscape VR, the virtual reality group, was the latest high-tech share to come down with a bump, crashing 72p to 598p after it warned of increased losses. The prospect of investment presentations next week also provided a spur.

But Thorn EMI gave further ground, off 15p at 1,790p.Rexam, the paper group, added 18p to 403p on talk of a Swiss bid and Hambros, the merchant bank where predators are thought to circle, rose 8p to 251p, largely on bullish comments by its Hambro Insurance Service offshoot, up 10p at 94p.Granada, celebrated its first Forte sale - 60 hotels to Regal Hotels for pounds 121.7m - with a 22.5p gain to 797p. Break-up talk again swirled around Pearson, up 20p to 721p, and Reuters rose 23.5p to 757p on share buy-back hopes. Reed International gained 20p to 11,64p and United News & Media, where Lord Hollick has moved in as chief executive, 18p to 684p. The supporting FT-SE 250 index, however, continued to outperform, climbing 25.4 to yet another high, 4,385.3. The market, therefore, treated with splendid indifference today's payroll figures.Last month they created havoc in New York, sending shares tumbling and, on the principle that when Wall Street sneezes London catches a cold, there was a sharp decline in domestic shares.But London seemed content with the long holiday wait until Tuesday before it can get to grips with the US data.Excitement continued in media shares with the market remaining on edge over potential bids and deals. NP gained 5p to 492p and PG 6.5p to 549.5p.The bid excitement helped lift the FT-SE 100 index 30.5 points to 3,755.6; it is only 25.7 from its February peak. With Whitehall expected to clear the bids for Southern Electric and Midlands Electricity by National Power and PowerGen the hunt was on for other likely targets. London Electricity, said to be in the sights of Thames Water, surged 20p to 793p - a 50p gain this week - and Yorkshire Electricity rose 15p to 857p, a 44p improvement over the four days.Speculation continues of further US interest in the sector and it is thought Yorkshire, currently making presentations to its institutional investors, is fearful of a transatlantic strike.Anticipating bid clearances.