The U.K. Financial Conduct Authority (FCA) is revamping the London Stock Exchange rules (LSE), but more changes may be needed to achieve growth and attract initial public offers (IPOs), experts said.

In a bid to create more business, the LSE is about to implement the most significant rule changes in 30 years. The FCA published a simplified listings regime that replaces the existing premium and standard categories with a single category, which will go into force July 29.

Ruth Prickett graduated from Cambridge University with a BA hons in History and has specialized in business and finance journalism for the past 20 years. She was editor of Financial Management, the magazine...