* Says risk of "hard Brexit" has increased
* Says likes euro, but has French election protection (Updates with quotes, context)
By Dhara Ranasinghe
LONDON, March 29 (Reuters) - BlackRock's head of global bonds said on Wednesday he remains invested in the British pound but has concerns over whether Brexit negotiations can be completed within their two year deadline.
British Prime Minister Theresa May will file formal Brexit divorce papers on Wednesday, starting a countdown to a divorce with the European Union in 2019.
"My main concern is around the timeline for trying to get these things done as quickly as we can," said Scott Thiel of BlackRock, the world's largest asset management firm.
"We are still positive on sterling but there are still...risks," he said, adding that the possibility of a "hard" Brexit if there is no agreement had increased.
Investors' main fear is that a "hard" Brexit -- one in which Britain would lose preferential access with its largest trading partner -- would hurt the British economy.
The better-than-anticipated performance of the economy following last year's referendum on EU membership has been a reason to be positive on sterling, Thiel said.
Britain's pound hit a two-month high of $1.2615 on Monday in a move driven chiefly by broader weakness of the dollar.
But uncertainty surrounding the terms of Brexit continues to weigh on the currency, which is down almost 20 percent against the dollar since the Brexit vote.
Thiel, who manages funds totalling about $41 billion assets under management, also said he likes the euro as an investment.
He added, however, that he had bought so-called put options on the single currency to protect against any market ructions stemming from the upcoming French presidential election.
A put option allows an investor the right but not the obligation to sell an asset at a later date and is often used as a hedge against risk.
French presidential elections in April and May are viewed as a key event risk for financial markets as one of the leading contenders is the far-right, eurosceptic candidate, Marine Le Pen, who wants France to ditch the euro.
"I like the euro generally but we have to recognise ... what we can't possibly know, and we can't possibly know the outcome of the French elections," Thiel said.
"Therefore I like to have downside option protection on the euro because if the French political situation were to go for the FN (Front National) then the euro would go significantly lower." (Editing by Gareth Jones)