Investors in TXU Corp. - due to vote in just two weeks on whether to sell the company to private equity firms for $32 billion - might want to take notice. The first major power deal in 16 months finally closed on Friday, putting at least a temporary end to a string of failures in the sector.

British power company National Grid, which announced plans in February of 2006 to buy KeySpan Corp. for more than $7 billion, finally made it through its last state regulatory hurdle this week.

The deal was announced amid a flurry of optimism in the sector about consolidation with deals that included Exelon Corp.’s plans to buy Public Service Enterprise Group, Duke Energy’s acquisition of Cinergy Corp., and FPL Group’s proposal to buy Constellation Energy.

Of them, only the Duke-Cinergy deal closed, in April of 2006. The others ended up on the scrap heap late last year as the companies fought with state regulators - newly empowered after a change in federal regulatory oversight seemed to open the door to more scrutiny - and local politicians.

Even small deals have been tough to come by. Just last month, Australia’s Babcock & Brown Infrastructure Ltd walked away from a $2.2 billion deal with NorthWestern Energy Corp. after state regulators had blocked the deal.

The failed deals have cut into M&A in the sector, as corporations look warily at how state regulators - who are tasked with making sure consumers get the best rate possible - will view their combinations.

TXU’s buyers, a group led by private equity firms Texas Pacific Group and Kohlberg Kravis Roberts & Co, have already made it past the state legislators and politicians, but they still need all the good karma they can get.

The buyers have to get past their largest shareholder, Franklin Resources, which has said the deal price is too low. And they have to sell all that debt that goes with the deal in markets that don’t seem too open to massive junk bond deals. Globally, some $330 billion of junk bonds from other leveraged buyouts are still waiting to be sold.