Tom Stevenson, investment director at Fidelity International, also warned that the U.K. vote on EU membership could affect the FTSE's prospects.
"Whether or not the rally can be sustained over the next couple of months will depend on how the Brexit polls evolve and the unfolding US earnings season, where expectations are low enough to offer the prospect of positive surprises," he said to CNBC in an email.
"In the meantime, with the FTSE 100 still 10 percent below last spring's peak level, U.K. shares offer attractive yield support in a lower-for-longer interest rate environment."
Khalaf also offered a positive outlook for the FTSE and said it was approaching a fair value for investors.
"The U.K. stock market valuation remains in the middle of its range, which suggests it's neither cheap nor expensive, so long-term investors are getting close to a fair price."
The worst performer on the FTSE was food retailer Tesco. Shares in the company slumped, despite reporting sales growth and pre-tax profits of £162 million ($230 million).
Follow CNBC International on Twitter and Facebook.