White & Case is in crisis talks with Saudi alliance partner Mohammed Al-Sheikh while Trowers & Hamlins' Saudi tie-up has split, as pressure on international firms to secure local law capability in Saudi Arabia intensifies.

White & Case is in 11th-hour talks to persuade Al-Sheikh to stay allied to the firm, with a decision expected in about a fortnight.

Under Saudi regulations, a local practice can only be opened by a Saudi national, leaving foreign firms dependent on a relationship with local lawyers for a presence in the region.

As part of its bid to save its alliance with Al-Sheikh, which was formed in 2005, the US firm is understood to have put forward proposals that include ramping up its fee earner numbers in Saudi Arabia and providing additional support from the network.

Meanwhile, the relationship between Trowers and alliance partner Hassan Mahassni, which began in 2005, has ended. Mahassni, who operates with a group of lawyers in the region, is understood to be considering entering into discussions with other foreign firms interested in opening in Saudi Arabia.

The news will be greeted with interest by a raft of international firms including Allen & Overy, Norton Rose and Linklaters, which are all known to be looking to open in the region.

Saudi Arabia has long been an area of interest for UK and US firms and, in the wake of multibillion-dollar deals such as the $9.8bn (£5.2bn) power project and a pipeline of other major transactions, firms have increased their search for Saudi law partners.

One local lawyer said: "With the current boom, there are numerous local and international firms looking to set up in the region."